Folding machine attachment



1961 D. w. MARVELLE 2,996,185

FOLDING MACHINE ATTACHMENT Filed Oct. 51, 1957 2 Sheets-Sheet 1 FIG. I

INVENTOR. DANIEL W. MARVELLE BY N ATTORN EYS 'Aug. 15, 1961 D W. MARVELLE FOLDING MACHINE ATTACHMENT 2 Sheets-Sheet 2 Filed Oct. 31, 1957 INVENTOR. DANIEL W. MARVELLE Hwy 610% ATTORNEYS United States Patent- 2,996,185 FOLDING MACI-IINE ATTACHMENT Daniel W. Marvelle, Newport, RL, assignor to Egans fialiungry and Cleaners, Inc., a corporation of Rhode Filed Oct. 31, 1957, Ser. No. 693,735 Claims. (Cl. 209-90) This invention relates to a machine for folding fiexible 1sheets of material and particularly the folding of bed men.

of an ironer in the laundry industry. Generally, the article to be folded is fed by means of conveyer belts from ironer rolls and to a folding machine wherein means are provided to effect longitudinal folds in a predetermined manner. In laundry procedures with which I am familiar, it is customary that the folding machine will be fed each article of laundry which may be ironed in a bundle of wash. Each article need not be folded particularly small articles such as towels and accordingly the main utility of the-folding machine, heretofore referred to, comes about when sheets and other large fabrics are fed thereto.

In the machines of the prior art there has been provided a manual control so that the operator of the machine may control which articles are to be folded as they are advanced towards the machine. Utilizing a system such as this, it will be apparent that certain errors are possible and that articles that need not be folded will accidently feed through the folding machine. fore, that some automatic means he provided which will sense the size of articles fed to the folding machine and determine whether they are to be passed into the machine or by-passed.

Accordingly, it is the main object of this invention to provide an automatic apparatus which activates a by-pass control on the folding machine that is operable in response to the size of the article fed thereto.

Another object of the invention is to provide a timing device in association with the sensing means which will allow a large article to pass into the folding machine without activating the by-pass device until a certain pre-set time has elapsed.

With these and other objects in view the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the drawings:

FIGURE 1 shows a side sectional view in elevation of a typical folding machine. i

FIGURE 2 is a perspective view of the top a typical folding machine; and

FIGURE 3 is an electric schematic of the vice'used in my apparatus.

In the drawings there is illustrated a typical folding machine which utilizes a plurality of ribbons 20 that travel around suitable guide rollers in a particular, path so as to feed material into the machine for folding operations. Basically the machine consists of a frame generally indicated by the reference numeral and which consist of,

two upright portions betweenwhich several guide rollers may be mounted. The ribbons 20 heretofore referred to. travel from a first guide roller (not shown) .to an upper guide roller 21 and thence back to the original roller to complete their, path. ,A piece. of sheet material is suitably fed to the ribbons 20 so as to be carried thereby in flat form and may either pass into the folding machine around roller 21 or be fed onto table 38 depending upon the position of the by-pass fingers 22. These by-pass fingers 22 are of generally arcuate shape and are mounted for rocking motion on a shaft 23 which extendsbetween the up- It is customary to utilize a folding machine at the end It is desirable, ther'e-- portion of timing deat: KB

2 right portions of the frame 10 and in close the upper roll 21.

In FIGURE 1 the fingers are shown in the open posiproximity to tion and in this position will allow a sheet of material to:

pass into the machine by feeding the sheet around the up-- per roller 21 and dropping the leading edge thereof onto further feeding ribbons 24. Since the folding operations form no part of this invention, no detailed description'is; made of this operation. If the fingers 22 extend between the ribbons it will be apparent that the sheet material will not pass around the roller 21 but will slide over the; roller since the fingers will raise the material sufliciently' so that it will not contact the ribbons 20 at this location and the sheet material will thence slide down the inclined plate 25. Rocking motion of the fingers 22 between open:

and closed positions is provided by a shaft 23 which has.

link arm 26 there is attached an operating rod 27 the end of which is attached to a pivotting arm 28 pivoted as at 29 to the frame of the machine. Attached to this pivotting arm 28 is an air motor 30. Operation of the air motor 30 will rock the arm 28 which in turn will rotate shaft 23- through the linkage just described and move the fingers 22 from the position shown in solid line in FIGURE'I to. the closed position shown in broken line.

To control the position of the fingers 22 and operation of motor 30 in response to the size of the material fed to the machine, and purely by way of example of one meth-- od, an electronic timing device and a sensing device 40 are shown, the timing device controlling an air valve, 'and in: turn, the air motor 30. The sensing device generally indicated 40 consists of a sensitive switch 41 having a sens ing element 42 in the form of a feeler finger extending" between two adjacent ribbons 20 as shown in FIGURE 2. This switch 41 is preferably mounted on a bracket 43 which extends over the traverse of the ribbons 20 being affixed to a transverse supporting member such as 11 that extends between the upright frame of the folding machine.

The timing and control circuity for the fingers 22is shown in FIGURE 3 and includes a vacuum tube 44 hav-" will be apparent to those skilled in the art, that unless the bias winding 48' is removed and a bias voltage with revacuum tube 44 is conducting current, relay 50 will be inactive. In order to modify the grid bias of the tube 44,

the switch 41 is efiectively connected directly across the- Switch 41 normally remains closed and bias winding 48'. accordingly tube 44 is normally conducting and relay 50 is activated, thus maintaining armature 55 thereof againstcontact 62. This position of armature 55 completes a circuit from a source of potential 56 to the coil 57 of a magnetic valve 58 and also to indicator lamp 60. With the coil 57 of the valve 58 energized, air from a source of supply (not shown) is allowed to pass through pipe 59 to air motor 30 which will cause the operating shaft 31 there-- of to be forced outwardly of the casing. This in turn Willmove the arm 27 and rock fingers 22 to the broken line 1 position shown in FIGURE 1 which has been termed the" closed position. In this position of the fingers 22, any article passing along the ribbons 20 will be lifted by the fingers 22 and passed down the plate 25 to the receiving table 38. However, as soon as a large sheet of material advances along the ribbons 20, the size of this sheet of material will be suflicient to have a portion thereof engage the sensing finger 42 which will then open switch 41."

When this occurs, the efiective short circuit across the annexes spect to. the cathode. 45. is. presented to the. gridv 46 by lead 51. Tube 44 immediately stops conducting and armature 55 swings to contact 63 de-energizing the coil 5.7, closing valve 58, and' lightingindicator'lamp 61. Air pressure having been removed from motor 30, the operating shaft 31 will return to a rest position under the influence of spring 32 and the fingers 22 will, rock to open position as shown in solid line in FIGURE 1. Accordingly the sheet of material is allowed to pass around roller. 21 and into the folding machine for a sequence of folding operations, eventually emerging from the machine down incline plate 37 and on to table 38. Eventually the rear' most edge of the material leaves finger 42 and the switch 41 and again closes. When this occurs, the negative bias is removed from lead 51 but the grid 46 remains at a negative voltage with respect to cathode 45 inasmuch as capacitator 53 has received a charge during the open position of switch 41 which keeps the grid at this negative voltage. The charge from capacitator 53v is slowly removed. by discharging through potentiometer 54 at a rate determined by the RC. constant of the circuit 52. -It will be apparent, therefore, that upon suitable selection of the circuit 52 constants a variable delay time may be had before tube 44 again conducts. Ac-

oordingly for a known speed of the ribbons a time the circuity just described and to that end there is provided a normally open switch 70 between grid 46 and the most negative side of bias winding 48'. Opening of this switch will immediately place a bias on the grid 46 of tube 44 operating relay 50, and allowing fingers 22 to open. Also should it be desired to maintain the fingers 22. closed irrespectively of any other operation. of. the. system, a switch '71 is provided which in parallel with the bias winding 48 to effectively shunt out this bias winding and assures that the fingers will remain close irrespective of the switches 41 and 70. -It will of course be apparent to those skilled in the art that one cannot directly short circuit a bias winding such as 48 into that end a bleeder resistance 72 is inserted into the short circuit path.

It will be apparent therefore that I have provided a device for association with a folding machine which will eliminate any manual operation of the by-pass fingers, and in effect selects articles to be folded on the basis of their size. A bed sheet is for example of a size so that it extends more than two-thirds of the transverse distance across the plurality of the ribbons 20. Accordingly, the sensing means is placed a location at which will insure that it is only operated when such a large piece is fed thereto. In practice it has been found that if the sensing means 40 is placed midway of the transverse distance of the ribbons 20 that more positive operation is had. In the position it will be almost impossible for a large sheet of material to pass the sensing means without activating it. Similarly, small pieces may be placed on either side of the sensing means to prevent activation the success of which will be determined somewhat by the operators skill in feeding work to the folding device.

It will be apparent to those skilled in the art that various substitutions may be made in the apparatus above described within the spirit of the claims appended hereto.

I claim:

1. In combination with a sheet-handling and folding machine having a plurality of endless bands, said bands being positioned side-by-side and spaced from each other for conveying sheets to said machine, a by-pass apparatus located at the end of said bands to selectively feed sheets of predetermined, sizes. into a machine or to a table, an electric switch having an operating finger depending therefrom in the space between adjacent bands at a location beneath the upper stretches of said bands and engaged by said sheets and moved thereby to operate said switch and an electrical circuit, means connected to said by-pass apparatus and. operable to normally move and hold the same at a location to block the passage of said sheets into the machine, said switch being in circuit with a timing device, said timing device being connected to said means and instantaneously responsive to the operation of said switch for operating said means and allowing said bypass apparatus to be moved from sheet blocking relation, the operated condition of said switch maintaining said means operative, said timing device holding said means operative after said switch returns to normal position a period suflicient to allow the entire sheet to pass into said machine.

2. In combination with a sheet-handling and folding machine having a plurality of endless bands, said bands being positioned side-by-side and spaced from each other for conveying sheets to said machine, a by-pass apparatus located at the end of said bands to selectively feed sheets of predetermined sizes into the machine or to a table, a motor connected to said by-pass apparatus and normally operable to move and hold the same to block said sheets for passing into the machine, an electric switch having an operating finger depending therefrom in, the space between adjacent bands at a location beneath the upper stretches of said bands and engaged by said sheets to operate said switch and an electrical circuit, said switch being in circuit with a timing device, said timing device instantaneously operating said motor in response to the operation of said switch whereby said motor actuates said by-pass apparatus to be moved from sheet blocking position, the operated condition of said switch maintaining said motor operative, said timing device holding said motor in operated position for a preset interval after said switch returns to normal position thereby allowing the trailing edge of the sheet to pass into the machine.

3. In combination with a sheet-handling and folding machine including a spaced endless band conveyor feed to said machine, a bypass apparatus located at the end of said conveyor to selectively feed sheets of predeter mined sizes into said machine, an air motor connected to said by-pass apparatus and operable for moving and holding the same at a position to block the passage of sheets into said machine, an air supply for said motor, valve means for controlling the air supply to said motor, a sensing means positioned substantially midway of the conveyor and having a finger movable relative to said conveyor and between a pair of bands to be engaged by a sheet of predetermined size and operated thereby, said. sensing means being coupled to a timing device, said timing device controlling said valve and instantaneously responsive to the operation of said sensing device for moving said valve to closed position thereby moving said by-pass apparatus from said sheet blocking position, said timing device preventing reactuation of said valve for a preset. time interval after said sensing means returns to normal condition so as to permit the trailing edge of the sheet to pass into the machine.

4. in a sheet-handling machine as set forth in claim 3 wherein said timing device includes a vacuum tube with RC network in the grid circuit thereof, a relay in the plate-cathode circuit of said tube, and a normally closed switch in the grid-cathode circuit of said tube, the finger of said sensing means operating said switch.

5. In an article folding machine for folding long textile articles and bypassing short textile articles and the like, the combination including a plurality of endless bands, said bands forming conveying means for transporting articles therethrough, said bands being positioned side by side and having finite spaces therebetween, conveyor driving means, bypass apparatus located at the end of a first stretch of said conveying means to selectively feed 5 textile articles into the machine or onto a table, sensing and measuring means located substantially midway of the transverse extent of the first stretch of conveyor bands, said sensing means having an operating finger extending into the space between adjacent bands, said sensing means operating timing means responsive to the passage of long textile articles and controlling said bypass apparatus, said timing means and conveyor driving means having their speed related so that the bypass apparatus will permit long textile articles to pass into said machine and to be folded thereby, said bypass apparatus being normally in a position to block passage of textile articles into said machine, short textile articles being permitted to pass on either side of said sensing means and over the bypass apparatus onto said table.

References Cited in the file of this patent UNITED STATES PATENTS 

